Abstract:Sugarcane (Saccharum sinensis Roxb) is an important sugar crop produced mainly in the subtropical and tropical regions of China.Wide row spacing (1.0-1.2 m) and initial slow growth rate of sugarcane offers a suitable space and resources (water,nutrition,light) niche for intercropping in sugarcane.A field experiment was conducted to study the effects of different sowing times of peanut on ecological factors of sugarcane-peanut intercropping and peanut yield.Seven treatments were used to evaluate appropriate sugarcane-peanut intercropping treatments.Results showed that peanut yield and the agronomic traits significantly increased in appropriate sugarcane-peanut intercropping treatments,especially in the IS3 treatment.The intercropping treatments significantly increased the concentration of soil ammonium nitrogen with 57.66%-85.69%.Meanwhile,it significantly decreased the concentration of soil nitrate nitrogen,especially in the IS3,IS4,IS5 treatments,which decreased by 24.33%-26.76%.The functional diversity and metabolic activity of soil microbial community was improved under intercropping,so did with soil microbial biomass carbon and nitrogen.Intercropping improved the condition of field microclimate.The soil microbial biomass carbon and nitrogen were significantly correlated with yield.It is indicated that appropriate sugarcane-peanut intercropping could obviously increase the peanut yield and the agronomic traits,which had significant ecological effects.